The present invention relates to container packaging systems. More particularly, it relates to transporting of containers within a packaging system, such as a system for packaging flowable food products in containers.
One area where the use of plastic containers has become widespread is in the food packaging industry. Accordingly, it is common for these plastic food containers to serve as the end display package as presented for sale to the customer. A number of different container configurations have been devised, although a few shapes are more prevalent than others. For example, frustoconical containers (i.e., having a sidewall that tapers from a larger diameter top to a smaller diameter bottom) are commonly used for products such as cottage cheese, sour cream, applesauce, or the like. Conversely, there are also currently available thermoformed containers that have a reverse tapered sidewall (or reversed frustoconical shape) with a larger diameter bottom. This type of thermoformed plastic food containers is typically used to package yogurt (e.g., flavored yogurt) as well as other products. A multitude of other plastic food container designs are also available (such as those having a non-tapering sidewall and/or non-circular in transverse cross-section), and can contain a wide variety of other types of products, that may or may not be food products.
Regardless of the exact container configuration, packaging systems used to produce filled containers on a mass production basis generally entail two or more stations at which the containers are loaded, filled, and closed. A drive system transports the containers from station-to-station. In the context of container packaging, conventional drive systems include carrier plates that are adapted to receive and maintain a number of individual containers. A series of the so-constructed carrier plates are linked to one another and driven in a conveyor-like fashion. The mechanism by which the individual containers are maintained relative to the carrier plate will vary, depending upon the container shape and related constraints. As a general statement, however, accepted container mounting techniques are premised solely upon receiving and supporting the container at or along an exterior surface thereof.
For example, U.S. Pat. No. 5,155,971 describes a packaging apparatus in which containers are sequentially transferred from a loading station to a filling station by a drive system including a plurality of transport carriers 12. More particularly, and as shown in FIG. 2 of U.S. Pat. No. 5,155,971, each transport carrier 12 includes a plate 38 forming a series of holes 40 sized to receive a container 14. Further, a support ring 41 and a plurality of posts 42 extend upwardly from the plate 38 at each hole 40. The container 14 is received within hole 40 and the ring 41 that otherwise contacts an exterior of the container 14. The posts 42 generally center the container 14 relative to the ring 41 via contact with a lip 36 of the container 14. The ring 41 does not tightly engage the container 14, but instead simply supports the lip 36. This approach is highly viable due to the frustoconical shape of the container 14 whereby the bottom 30 of the container 14 has a smaller diameter as compared to the top/lip 36. In this manner, the container 14 slides within the hole 40 and the support ring 41 such that the lip 36 (or top) of the container 14 is fully supported by the plate 38 in an upright position. Thus, the container 14 will not readily tip relative to the plate 38.
While the above-described transport device configuration is well accepted, it can only be used with frustoconically-shaped containers whereby the desired, upright container orientation places the smaller diameter end below the larger diameter end. For example, and again with reference to FIG. 2 of U.S. Pat. No. 5,155,971, were the container 14 orientation to be reversed (i.e., the smaller diameter end 30 being open and oriented above a closed, larger diameter end 36), the container 14 could not be received over or within the ring 41. Similarly, a uniform diameter container (e.g., defining a right cylinder, other shapes with non-tapering sidewalls, etc.) could not be supported by the ring 41. A common technique for addressing this problem is to simply remove the ring 41, leaving only the posts 42. One example of this configuration is shown in FIG. 1 of the present application that otherwise illustrates a container 50, a carrier plate 52, and groupings of three posts 54. As a point of reference, the carrier plate 52 of FIG. 1 is adapted to maintain up to five containers, but is illustrated as supporting the one container 50. The container 50 of FIG. 1 has a reversed frustoconical shape including an open, top end 56 and a closed, bottom end 58, with the bottom end 58 having a diameter greater than a diameter of the top end 56. The container 50 is maintained relative to the carrier plate 52 by a set of the three posts 54 equidistantly spaced about a hole 60 in the carrier plate 52 (it being understood that the hole 60 associated with the container 50 is hidden in the view of FIG. 1). A diameter of the hole 60 is less than that of the container bottom end 58. That is to say, the bottom end 58 rests on the carrier plate 52, with the posts 54 preventing overt movement of the container 50 via periodic contact with the bottom end 58. Notably, due to machining tolerance requirements, a collective diameter defined by a spacing of the posts 54 is greater than a diameter of the bottom end 58, on the order of 0.25 inch. As such, the container 50 readily moves between the posts 54 (for example, upon movement of carrier plate 52), possibly leading to alignment concerns. Perhaps even more problematic is the ease with which the container 50 can tip relative to the carrier plate 52. In particular, and especially prior to filling, a center of gravity of the container 50 is at or above a height of the posts 54. Thus, with movement of the carrier plate 52 and thus movement of the container 50, the container 50 can easily tip over the posts 54, causing major delays in production. With taller containers, this tippage concern is amplified.
Packaging systems for handling, transporting, filling, and closing containers on a mass production basis are widely employed in the packaging industry. Unfortunately, for many container configurations, accepted transport devices are unworkable and/or less than optimal. As such, a need exists for an improved container transport device and method for use with product filling systems.